1. Field of the Invention
The present invention relates to a moving image playback apparatus, a moving image playback method, and a program thereof. For example, the present invention can be applied to a playback apparatus for playing back a moving image from a recording medium, such as a hard disk, an optical disc, or the like. In the present invention, moving image data, which has been produced by delta-sigma modulating a moving image for each pixel into delta-sigma modulated data, is recorded onto a recording medium. At playback time, the delta-sigma modulated data is subjected to filtering processing for each pixel to be converted into video data. Thus, the present invention allows a user to play back a user-desired moving image with higher definition than before.
2. Description of the Related Art
To date, in a camera-integrated recording and playback apparatus, an output signal produced by raster scanning from an imaging device has been subjected to analog-digital conversion processing, then has been subjected to white-balance adjustment, color-conversion processing, exposure compensation, etc., and has been recorded onto a recording medium. Also, a shutter speed has been set by the setting of charge-storage time of the imaging device. Also, a frame rate has been set by the setting of the drive signal of the imaging device. At the same time, a fast-forward playback has been carried out at playback time by thinning consecutive frames to be output, and a moving image has been played back in slow motion by repeatedly outputting a same frame at time intervals in accordance with a playback speed.
On the other hand, in recent years, new still image recording apparatuses, such as digital cameras, etc., have appeared in the marketplace. These apparatuses can omit white-balance adjustment, color-conversion processing, exposure-compensation processing, etc., and record RAW data, which is obtained by analog-digital conversion of the output signal of an imaging device, directly onto a recording medium. In the case of directly recording this RAW data, it is possible to reduce deterioration of image quality and to make various adjustments on the image quality at playback time compared with the case of performing white-balance adjustment, color-conversion processing, exposure-compensation processing, etc., before recording.
On such an imaging apparatus, International Publication No. WO2006/25232 specification has disclosed a configuration in which a result of photoelectric conversion by an imaging device is delta-sigma modulated for each pixel.
Incidentally, in a related-art playback of a moving image, techniques are not yet sufficient to output a moving image with the high definition that users desire.
That is to say, in a related-art playback of a moving image, when a playback in slow motion is carried out, a same frame is repeated in accordance with a playback speed, and thus it becomes difficult to play back the moving image with a smooth motion. Moreover, in this case, motion blurring also occurs. On the contrary, when a fast-forward playback is carried out, consecutive frames are thinned to be played back, and thus a motion becomes sporadically skipped. Thus, it also becomes difficult to play back the moving image with a smooth motion in this case. Accordingly, there has been a problem with a related-art playback of a moving image in that it is difficult to output a moving image with high definition that a user desires regarding a playback at a variable speed.
In this regard, in a slow-motion playback, as a method of smoothing a motion and to further prevent motion blurring, a method of obtaining an imaging result at a high frame rate and then outputting the moving image at a low frame rate through a recording medium is considered. However, in this case, when a playback is carried out at a normal playback speed, consecutive frames are thinned to be played back in the same manner as the case of the fast-forward playback described above. Accordingly, a motion becomes sporadically skipped, and thus, it also becomes difficult to play back the moving image with a smooth motion in this case. Also, in this case, a jerkiness disturbance occurs. Also, the same problem occurs in the case of a fast-forward playback. In this regard, in this case, a method of creating one frame by combining a plurality of frames by interpolation calculation processing of the image data is considered. However, in this method, there is a problem in that it becomes necessary to provide a buffer having a large storage capacity additionally, and the configuration becomes complicated.
Also, in a related-art playback of a moving image, when a content includes a fast-moving image, such as a sport, etc., it is possible to capture the image by a fast-speed shutter, and to play back the moving image with little motion blurring at playback time. Also, when a content includes a slow-moving image, such as a drama, etc., it is preferable to capture the image by an open shutter. However, in the related-art playback of a moving image, it is not allowed to vary the shutter speed at playback time, and thus there is a problem with the setting of a shutter speed in that it is difficult to output a moving image with high definition that a user desires.